To study the effect of antler on spermatogenesis, six cocks were administrated six times with 1.5g of antler per each cock, and other six cocks were allocated as the control group. The quality of the semen ejaculated at the interval of 72, 48, 24, 12, 6, 3, 1 hour and the testicular tissue were observed. 1. The amount of ejaculated semen, the number of sperm, the viablility of sperm, methylene blue reduction time and fertilization rate were increased in the antler administrated group compared with the control group. 2. Spermatogenesis was more active in the antler administrated group than in the control group when the testicular tissue were compared between two groups.